New studies show that the volcano’s underground magma system is larger than previously measured and may extend outside the known caldera boundaries. The estimated total volume of magma down there, scientists say, is around 48-144 cubic miles (200-600 cubic km) – much more than earlier estimates. However, it’s 85% to 95% solidified and so very difficult to erupt. The Yellowstone Volcano Observatory says these new findings do not mean increased geologic hazard at the volcano and don’t increase the chances of a supereruption in the near future.
Another earthquake swarm is ongoing, with around 1,800 recorded between January 17 and February 8. The strongest is a magnitude 3.8. According to University of Utah experts, such swarms are common, with the volcano having had 80 such swarms in the past 15 years.
The Yellowstone Volcano Observatory reports that uplift of the caldera floor is slowing. Since mid-2004, the northeastern part of the caldera has risen some 9 inches (23 cm). Scientists suspect that snow melt and groundwater recharge may be slowing down the rate of uplift, but they also say that, as in earlier episodes, the uplift might continue later in the year.
A swarm of more than 250 small earthquakes, centered on the northwest end of Yellowstone Lake, continues. The tremors have ranged from magnitude 3.8 down to barely detectable. Scientists are unsure what is causing them.
Science magazine reports that the volcano’s caldera has been rising at a rate of up to 3 inches per year since mid-2o04. Scientists believe the uplift is due to an infusion of magma some 6 miles underground. However, study co-author, Robert Smith, of the University of Utah says that there is no evidence an eruption or hydrothermal explosion is imminent.
National Park Service FAQ reports there is no evidence that a caldera-forming eruption is imminent. Although theoretically possible, such a catastrophe is unlikely to happen in the next 1,000 to 10,000 years. If the volcano erupts at all, it will most likely have slow, oozing lava flows. However, no scientific evidence suggests that such smaller events are coming, either.
Higher than normal ground temperatures and increased thermal activity force the closure of several trails for visitor and employee safety. Yellowstone Volcano Observatory scientists deploy a network of seismographs, GPS receivers and thermometers, making Norris the most heavily studied geyser basin in the world.
The University of Utah, the United States Geological Survey and Yellowstone National Park establish the fifth volcano observatory in the United States. Instead of a building, scientists will use existing facilities and equipment at the park, as well as at the University of Utah and in USGS offices in California and Washington State, to monitor real-time earthquake and ground deformation.
Several geologists tell the British Broadcasting Company how an unusual fossil discovery has led to the realization that the volcano is actually a one of the largest supervolcanoes on the planet. The magma chamber, they report, is 40-50 km long, some 20 km wide, and about 10 km deep. A supereruption today would cause unparalleled devastation.